Cargo-handling apparatus



Oct. 8, 1968 R. c. BURNETT CARGO-HANDLING APPARATUS 2 Sheets-Sheet 1 Filed Oct. 27, 1966 INVENTOR.

1968 R. c. BURNETT 3,404,911

CARGO-HANDLING APPARATUS Filed Oct. 27, 1966 2 Sheets-Sheet 2 RICHARD C. BURNETT TORNEY United Sta s at Q CARGO-HANDLING APPARATUS Richard C. Burnett, Claymont," Del., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jerseyv r Filed Oct. 27, 1966, Ser. No. 590,030

. 2 Claims. (Cl. 29481).

ABSTRACT OF THE DISCLOSURE,

' i A rectangular spreader for lifting containers is rigged to a single-point suspension by means of two flexible members each of which passes around a respective pair of aligned wheels located at opposite ends of thelonger sides-of the spreader. Reversible driving means are provided on the spreader for so driving the wheels that the ends of the members'move in a direction parallel to the longer sides of the spreader.

This invention relates to apparatus for handling cargo,

and more particularly to apparatus for handling loaded containers of a standard size and construction.

Recently, there have come into use hexahedral cargo i containers which'are of standard size and construction. In use, cargo is stowed in such containers and the containers are then closed, following which they are transported (via truck, for'example) to a port for loading aboard ship by means of cargo handling apparatus (gear) carried by the 'ship. The'present invention relates to the last-mentioned apparatus or ships gear.

The hexahedral cargo containers previously rrien-' 'tioned 'are, of course, of rectangular configuration seen plan, and are generally of one or the other of 'two simply a spreader) fabricated from steel and having a rectangular outer configuration conforming to the length and width of the containers to be handled. For

lifting purposes, the containers are provided with fittings of standard design at each of the four top corners thereof,

and the frame carries mating latch-type fittings, whereby the container may be fastened to the frame for suspen- "sion therebelow. That is to say, the container may be carried by the frame. The frame is in turn lifted by the ships gear, for example by means of the ships hoist or winch, which latter is a power-driven lifting device; The lifting of the frame is accomplished, in effect, at a single point, e.g. by means of a double-ended cargo hook mounted at the free end of a wire rope leading from the ships winch or hoist and engaging a sling-like arr'angement secured to the frame near the four corners thereof. Very often, the container to be handled is loaded eccentrically, that is, in such a manner that the resultant center of gravity of the loaded container is displaced from the spatial center of the container. Then, the singlepoint suspension of the frame (assuming that this point is originally directly above the spatial center of the container, which will ordinarily be the case) results in the tilting of the frame (and also, ofcourse, of the container) to an undesirable angle (with respect to the horizontal) when such eccentrically-loaded container is suspended from the frame. It is desirable to be able to counteract this tilting (thereby to trim the frame and con-- while the container is suspended from the frame; This counteractingoperation is known as leveling or trimming of 'the frame (spreader). One way of accomplishing this trimming is to, in effect, move the point of suspension of the frame to vertical alignment or near-alignment (the latter assuming that trimming to a small angle from the horizontal is desired) with the center of gravity of the loaded container. i

An object of this invention is to provide a novel self- Ieveling or self-trimming spreader assembly. Y

' Another object is to provide "a self-leveling spreader assembly which is of rather simple construction and thus requires a'minimum of maintenance. A further object is to provide a self-leveling spreader assembly which is designed for facile operation and which is capable of rectifying a large degree of eccentricity of the load, in either direction from the center of the container and parallel to the longer dimension thereof.

The objects of this invention are accomplished, briefly, in the following manner: Two pieces of chain are utilized, each chain passing in non-slip fashion around a respective pair of spaced sprocket wheels rotatably mounted on the respective longer sides of a rigid rectangular spreader frame and each chain having its two ends located above the frame. The frame is adapted to be secured to the container to be lifted, and means are provided for coupling the four ends (of the two chains) to the cargo hook of a common power-driven lifting device. Means, comprising in part a reversible electric motor mounted on the frame, is provided for rotating one sprocket wheel of each pair in the same selected direction, thereby driving said chains to move all four ends thereof in a direction parallel to the longer side of the frame, these ends being moved toward one end or the other of the longer side of the frame depending upon the direction of rotation selected for the sprocket wheel rotation.

A detailed description of the invention follows, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front elevation of a spreader frame assembly according to this invention;

FIG. 2 is a top plan view of the assembly of FIG. 1, certain parts thereof being omitted; and

FIG. 3 is a side elevation of the upper portion of the assembly of FIG. 1, certain parts again being omitted.

Now referring to the drawings, a rigid frame 1, fabricated from structural steel, has a rectangular outer configuration (shown in FIG. 2) which conforms in length and width to the known, standard dimensions of the containers (not shown) to be handled. On its lower side, at each of its four corners, the frame 1 carries respective latch-type fittings 2 (depicted somewhat schematically in FIG. 1) each one of which is located and constructed to mate with a respective one of the fittings provided at each top corner of the container to be handled. By means of the fittings described, the container may be suspended from or below the frame 1, and may be lifted by the frame when the latter is itself lifted. The fittings 2, as well as the fittings provided on the containers, are standardized in design, so that the frame 1 will fit any and all containers to be handled. The frame 1 has sufficient strength to lift containers having the maximum weights previously mentioned.

Along one of the longer sides of the frame 1, and near the right-hand end thereof, a sprocket wheel 3 is rotatably mounted on the frame. Sprocket wheel 3 is mounted on a stub shaft journaled for rotation in a pair of bearings and 6 which are each supported bya respective bracket (angle pillow block) 7 (FIG. 1) welded to the upper side of a cross brace forming a part of frame 1. The sprocket wheel 3 is thus located somewhat above the top side of the body of frame 1. The axis of shaft 4 extends transversely to the longer sides of the frame 1.

Along this same longer side of the frame 1, "and near the left-hand end thereof, a sprocket wheel 8 is rotatably mounted on the frame, wheel 8 lying in the same vertical plane as wheel 3 and thus being laterally aligned therewith. Sprocket wheel 8 is fastened (e.g., keyed) to a driven shaft 9 (adapted to be driven in a manner described hereinafter) which extends across frame 1 and whose axis extends transversely to thelonger sides of the frame. At one end, shaft 9 is journaled for rotation by means of a pair of bearings 10. and .11 which are each supported by arespective bracket. (angle pillow block) 12 (FIG. 1) welded to the. upper side of a cross brace forming a part of frame 1. The sprocket wheel 8 is thus located somewhat above the top side of the body of frame 1. At its outer end (adjacent the other of the two longer sides of frame 1), shaft 9 is journaled in a pair of bearings 13 and 14 which are similar to bearings and 11, and are similarly secured to frame 1.

A bracket .15, welded to one of the cross brace membersforming a part of frame 1, is utilized to rotatably support a guide roller (for example, a flanged truck wheel) 16 which is located near the lower side of the body of the frame and slightly toward the center thereof from wheel 8. Guide roller 16 lies in the same vertical plane as wheels 8 and 3 (see FIG. 2), and thus is laterally aligned therewith.

A bracket 17, welded to one of the cross brace members forming a part of frame 1, is utilized to rotatably support a guide roller 18 (similar to guide roller 16, previously mentioned) which is located near the lower side of the body of the frame and slightly toward the center thereof from wheel 3. Roller 18 (which, for the sake of simplicity, has been omitted from FIG. 2) lies in the same vertical plane as wheels 8 and 3 and roller 16, and thus is laterally aligned therewith.

A length of tubing 19, whose ID. is sufficient to permit .21 one-inch alloy chain to freely pass therethrough from one end to the other, is mounted near the lower side of the body of frame 1 between rollers 16 and 18 and in lateral alignment therewith, the center line of this tubing lying in, or slightly below, the plane which passes through the lowermost points on rollers 16 and 18. The tubing 19 serves as a chain cover.

Items 3-8, inclusive, and 15-19, inclusive, are all duplicated at the other (or opposite) longer side of frame 1; insofar as possible, parts like those previously described, but located at the other side of the frame, carry the same reference numerals but with prime designations.

Sprocket wheel 3', on stub shaft 4 near the right-hand end of the frame 1, is rotatably mounted on the frame. Sprocket wheel 8, fastened (e.g., keyed) to shaft 9 near the left-hand end of the frame 1, is rotatably mounted on the frame and is laterally aligned with wheel 3'. Wheels 3' and 8 may be considered to be mounted at spaced points along the longer side of frame 1 opposite to the longer frame side on which wheels 3 and 8 are mounted. Guide roller 16', opposite to guide roller .16, is rotatably supported on the frame 1 and is laterally aligned with wheels 3' and 8'. There is also a guide roller opposite to guide roller 18 (but which is not shown in the drawings) which is rotatably supported on the frame 1 and is laterally aligned with wheels 3 and 8, and with roller 16. Also, a length of tubing opposite to tubing 19 (but which is also not shown in the drawings) is secured to frame 1 between the two guide rollers on the other longer side of the frame. This latter length of tubing, like tubing 19, serves as a chain cover.

The double-ended cargo hook 2 0 (5*... FIG. 1 is a part of the ships gear (cargo handling apparatus) and,

specifically, is mounted at the end of a wire rope (not shown) leading from the ships winch. The frame 1 is suspended from the cargo hook 20 by means of two fiftyton pear rings 21 and 22, one on each end of the doubleended hook 20. Note that, for simplicity, the cargo hook is not shown in FIG. 3. Attached to each pear ring are two wire rope pendants (wire rope slings) of equal length, the two pendants 23 and 24.fo r a single pear ring such -as 2.1--making an angle of about; 30 with each other in the assembled device, as indicated in FIG. 3. Only one pendant is illustrated for each ring in FIG. 1, since the two pendants on each ring are alignedfront-to-rear; thus, only a single pendant 25 is illustrated on ring 22 in this figure.

As may be appreciated, there are four wire rope pendants altogether, two attached to each of the two pear .rings 21 and 22. The two pendants 23 and, 24 may be thought of as correlated, since they areboth attached to the same pear ring 21. Likewise, the pendant 25 and the other pendant at-ached to ring 22 may be thought of as correlated, sincethey are both attached to the same pear ring 22.

The lower ends of the correlated pendants 23 and 24 are connected by means of respective twenty-five-ton shackles 26 and 27 to respective opposite ends of a rigid spacer (leveling bar) subassembly 28. The subassembly 28 (see FIG. 3) comprises a piece 29 of six-inch pipe having a length conforming to the standard width of the containers to be handled, and having elongated lugs 30 and 31 (formed from steel plate) mounted respectively at the ends of the pipe, the lugs 30 and 31 extending through the pipe 29 at right angles to the axis thereof and being rigidly secured to the pipe. The shackle 26 is attached to the lower loop of pendant 23 and to the upper end of lug 30; the shackle 27 is attached to the lower loop of pendant 24 and to the upper end of the opposite lug 31. Thus, the lower ends of pendants 23 and 24 are maintained a fixed distance apart, by means of the spacer subassembly 28. The arrangement is such that the center line of lug 31 lies substantially in the same vertical plane as wheel 8, and the center line of lug 30 lies substantially in the same vertical plane as wheel 8.

The lower ends of the correlated pendants 25, etc. are connected by means of structure exactly similar to that described in the preceding paragraph (including a shackle 32 attached to the lower loop of pendant 25) to respective opposite ends of a duplicate rigid spacer (leveling bar) subassembly 33. In FIG. 1, the leveling bar 28 is located at the left-hand end of the spreader 1, and the leveling bar 33 is located at the right-hand end of the spreader.

Preferably, end closure plates are employed at each end of pipe 29, and also at each end of the similar pipe of subassembly 33.

One end of an elongated continuous flexible load-supporting member 34 (for example, a one-inch alloy link chain) is attached to the lower end of a link member 35 (for example, a twenty-five-ton double clevis link), and the upper end of link 35 is attached to the lower end of lug 31. Thus, this end of chain 34 is coupled through elements 35, 28, 27, 24, and 21 to cargo hook 20, and this end of chain 34 is, of course, located above frame 1. From link 35, chain 34 passes in non-slip fashion around sprocket wheel 8, then downwardly and under guide roller 16, through chain cover tubing 19, under guide roller 18, then upwardly and in non-slip fashion around sprocket wheel 3 to the spacer subassembly 33. At this latter subassembly (which, as previously noted, is above frame 1), the other end of chain 34 isattached to the lower end of a link member similar to link 35 and located at the front (as viewed in FIG. 1) side of spaced subassembly 33. It may be appreciated, from what has gone before,

, '5, that chain 34, which passes around the sprocket wheels 8 and 3, is located at one of the longersides of frame 1 (to wit, the front side as viewed in FIG. 1).

One end of another elongated continuous flexible loadsupporting member 36 (for example, alink chain exactly similar to chain 34) is attached to the lower end of a link member 37 similar to link 35, and the upper end of link 37 is attached to the lower end of lug 30. Thus,,this end of chain 36 is coupled through elements 37, 28, 26, 23, and 21 to cargo hook 20, and this end of chain 36 is, of course, located above frame 1. From link 37, chain 36 passes in non-slip fashion around sprocket wheel 8', then downwardly under guide roller 16, through the chain cover tubing located at the rear side of the frame, under the guide roller opposite to roller 18, then upwardly and in non-slip fashion around sprocket wheel 3' to the spacer subassembly 33. At this latter subassembly, the other end of chain 36 is attached to the lower end of a link member similar to link 37 and located at the rear side of spacer subassembly 33. It will be appreciated that the chain 36 which passes around the sprocket wheels 8' and 3', is located at the other of the longer sides of frame 1 (to wit, the rear side as viewed in FIG. 1).

It is pointed out that the right-hand ends of chains 34 and 36 are coupled to the cargo hook 20 through the spacer subassembly 33, the shackle 32 and another shackle directly behind it, the pendant and another pendant directly behind it, and pear ring 22. The chains 34 and 36 support the weight of the frame 1 and its load (the container suspended therefrom) mainly by way of the guide rollers 16, 16', 18, etc.; the chains pass under the respective guide rollers, and the latter are secured to the frame. That end of front chain 34 which is attached to lug 31 and that end of rear chain 36 which is attached to lug may be thought of as correlated ends of the two chains, since both of these ends are attached to the same spacer subassembly 28. Likewise, the other ends of the two chains, both of which are attached to spacer subassembly 33, may be thought of as a pair of correlated ends of the two chains.

It may be noted that the cargo hook 20, the chains 34 and 36, and the elements which couple the chains to the cargo hook have been omitted from FIG. 2; this has been done in order to simplify the drawings.

An electric motor-speed reducer combination 38, 39 is mounted on the upper side of frame 1 adjacent shaft 9, being suitably secured to the upper side of a cross brace forming a part of the frame. The output shaft of the motor 38 is coupled to the input side of the speed reducer 39. A roller chain sprocket 40 is secured to the output shaft 41 of the speed reducer 39, and a roller chain sprocket 42 which is laterally aligned with sprocket 40 is secured to the rotatable shaft 9. A drive chain 43, which may be a standard roller chain provided with a suitable cover (not shown) is operatively coupled to sprockets 40 and 42. The arrangement is such that motor 38 can cause rotation of shaft 9, through speed reducer 39 and drive chain 43.

The motor 38 is of reversible type, and is arranged for selective manual control (to cause the motor to rotate in one direction or the other, selectively) from a remote point (such as a point convenient to the ships winch platform) by means of a cable (not shown) connected between the motor and a suitable switch box located at the remote point.

The self-leveling action of the spreader of this invention will now be described. Assume that the container being handled is eccentrically loaded such that the center of gravity of the frame plus its load (container) is to the left of the illustrated central position of hook 20. In this case, the manual motor control would be operated to cause motor 38 to drive shaft 9 in the counterclockwise direction, rotating sprocket wheels 8 and 8' in the counterclockwise direction, as viewed in FIG. 1 The rotation of the sprocket wheels in this direction drives the chains 34 6 and 36 in the direction to shorten the horizontal component of the span of the chains on the left-hand side of the frame (i ;e.,' the side corresponding to spacer subassembly 28) and to lengthen the horizontal component of the chain span on the' right-hand: side of the frame' (i.e., the side corresponding to spacer subassembly 33). This movement of the chains, of course, involves rotation of the sprocket wheels 8, 8, 3, 3' and the guide rollers 16, 18, etc. in the "counterclockwise direction, andmove'ment' of the chains from. left to right through the tubular chain covers such as 19. This causes movement of the ends of the chains 34 and 36 parallel to the longer sides of the frame 1, in the direction indicated by arrows 44. This movement of the chains causes relative movement to take place between the frame 1 and the cargo hook 20 in the direction 44. For convenience, this is indicated in FIG. 1 as inovement of the hook 20 toward a left-hand limiting position 2011 wherein the hook is located vertically above the sprocket wheels 8 and 8'; however, it will be appreciated that what actually happens is that the hook 20 remains substantially stationary and the frame 1 moves toward the right therebeneath.

In any event, the point of suspension of the frame (determined by the single cargo hook 20) moves away from the spatial center of the frame and of the container, in the direction toward the actual center of gravity of the frame plus load. If the proper amount of movement of the chains is made to occur, the eccentrically loaded container may be trimmed to a horizontal or other suitable angle while suspended from the frame; in other words, the spreader or frame 1 may be kept in a continuously level attitude irrespective of the Weight distribution in the container being lifted thereby.

It is pointed out that, if the eccentricity of the container loading has the opposite sense, such that is center of gravity is to the right of the illustrated central position of hook 20, the motor 38 is energized in the opposite sense, so as to drive shaft 9 in the clockwise direction. As a result, the chains 34 and 36 are in this case driven to lengthen the horizontal component of the chain span on the left-hand side, and to shorten the horizontal component of the chain span on the righthand side. The ends of the chains again move-parallel to the longer sides of the frame 1, but now in the direction indicated by arrows 45. In effect, the hook 20 now moves toward a right-hand limiting position 20b wherein the hook is located vertically above the sprocket wheels 3 and 3'. The point of suspension of the frame again moves away from the spatial center of the frame and of the container, in the direction toward the actual center of gravity of the frame plus load. Trimming of the eccentrically loaded container will again take place.

It will be appreciated that, for either sense of trimming, a horizontal position of the frame results when the single point of suspension of the frame is directly above the center of gravity of the frame plus load.

The invention claimed is:

1. Apparatus for handling a loaded hexahedral container of standard size, comprising a rigid frame having a rectangular outer configuration conforming to the length and width of the container to be handled and adapted to be secured to a standard container for suspending of the latter below said frame; a first pair of wheels aligned with each other in a direction parallel to the longer sides of said frame and rotatably mounted respectively at spaced points along one of the longer sides of said frame, the individual axes of rotation of said pair of Wheels being parallel to each other and being perpendicular to the longer sides of said frame; a second pair of wheels aligned with each other in a direction parallel to the longer sides of said frame and rotatably mounted respectively at spaced points along the other longer side of said frame, the individual axes of rotation of said second pair of wheels being parallel to each other and being perpendicular to the longer sides of said frame; a first elongated flexible load-supsaid frame and passing in non-slip fashion around the indiyidual wheels of said second pair, means for coupling the ends of said firstv and second members to a common power-driven lifting device, and means for rotating one wheel of each pair in a common direction, thereby driving said members to move all of the ends thereof in a direction parallel to the longer sides of said frame.

2. Apparatus as defined in claim 1, wherein said r0- tating 'means'incl udes an electric motor mounted on said frame and having its output shaft mechanically coupled to the said one wheel of each pair.

References Cited UNITED STATES PATENTS 2,020,306 11/1935 Fitch 294-67 3,021,166 2/1962 Kempcl 61 a1. 294-44 3,075,664 1/1963 Collings 214658 3,191,983 6/1965 'EVON C. BLUNK, Primary Examiner. R. D. GUIOD, Assistant Examiner. 

